| 摘要 |
PURPOSE:To lessen abrasion of a piston ring by cancelling a force radially applied by pressure of a compression sapce so that the piston ring and the inner periphery of a cylinder slidably contact each other under high surface pressure. CONSTITUTION:The lower surface 24 of the second ring 2 of a piston ring is closely adhered to the upper surface 430 of the concave portion of a piston ring groove 4 by piston top land pressure which works thereon through the piston ring groove from the upper surface 22 of the second ring 2. Thus, the contact surface is extremely strongly pressed so as to obtain a strong sealing therein. In order to eliminate a radial force worked on the piston ring by pressure of a compression space, it may be good that h3=h2=h1/2. A pal is provided with a step 15 disposed axially, that is, a step-cut pal, thereby to prevent leakage of gas from the outer peripheral surface. |
